1. Field of the Invention
The present invention relates to a method for temporarily fixing various members when processing those members, and a composition suitable for the temporarily fixing. For example, the present invention relates to a method for temporarily fixing a translucent rigid substrate, such as a glass plate, when processing those members. The present invention further relates to a two-component type adhesive composition which is photocurable and curable at ordinary temperature, and which is suitable for the above-mentioned use.
2. Description of the Related Art
For processing optical lens and optical members, and optical device, prism, members for semiconductor packaging and the like, an adhesive for temporarily fixing those members is employed. In display unit of various electronic devices such as a television, a notebook computer, a car navigation, an electronic calculator, a mobile phone, tablet computer, an electronic organizer, and a PDA (Personal Digital Assistant), displays such as a liquid crystal display (LCD), an organic EL display (OLED), an electroluminescence display (ELD), a field emission display (FED), and a plasma display (PDP) are used. In addition, a plate glass product for protection is placed to cover such a display in order to protect the display element. Recently, a specified printed pattern, for example, patterning for display screen image of a mobile phone, is often formed on the surface of the protection plate glass product in view of designing aspect. In most of cases, light does not transmit through those printed patterns.
The plate glass product is obtained by processing plate glass to have a size and shape which are suitable for each display unit. An adhesive for temporarily fixing is needed in order to make it possible to process a large amount of plate glass products with high production efficiency in order to meet market requirements for a certain price level.
Patent Document 1 proposes a photocurable adhesive composition which controls a glass transition temperature of a cured body of resin and which contains in a suitable amount particulate matters being insoluble in resin composition, and a method for temporarily fixing by using the composition.
Patent Document 2 describes an adhesive composition for temporarily fixing which has large water absorbability of a cured body of resin and large solubility in water, and which peels members in warm water after processing the members. It is also described that such adhesive composition may improve workability, since it is easy to adjust its viscosity, so that those could be filled in clearance gap where a low viscosity adhesive would flow out and padded by themselves.
Patent Document 3 describes an adhesive composition for temporarily fixing chip members comprising a crosslinkable compound having ethylenic unsaturated bond, a monomer containing at least one acidic phosphate group and at least one unsaturated bond, thermal polymerization initiator, inorganic filler and/or thixotropic agent, and photopolymerization initiator.
Patent Document 4 describes a two-component type photocurable adhesive composition for optical discs wherein the light-irradiated area is cured to the second and wherein non-irradiated area is cured in a short time by two-component reaction.
Patent Document 5 describes a method for temporarily fixing members comprising fixing members temporarily by two-component adhesive, processing the temporarily fixed member, and immersing the cured body of the composition in warm water of 90 degrees C. or less to release the processed members, wherein the two-component adhesive comprises (A) a polyfunctional (meth)acrylate, (B) a mono-functional (meth)acrylate, (C) a conducting substance, (D) a polymerization initiator and (E) a polymerization accelerator, composed of two-component system of a first agent and a second agent; said first agent containing at least (D) a polymerization initiator and said second agent containing at least (E) a polymerization accelerator.